Mandrel-bar cap



Aug. 23, 1938. w. 'r. WEHMAN MANDREL BAR CAP Filed Jan. 25, i938 Patented Aug. 23, 1938 MANDREL-BAR CAP William T. Wehman, Eiyria, Ohio, assignor to National Tube Company, a corporation of New Jersey Application January 25, 1938, Serial No. 186,879

3 Claims.

A tube mill is ordinarily provided with mandrels of difierent sizes to accommodate diiierent work diameters. These mandrels are fixed to the mandrel-bar of the mill by a cap which conventionally provides an integrally projecting 5 mandrel-pin. When mandrels of diiferent sizes l heavy thrusts to the mandrel-bar and so becomes jammed.

The present invention relates to these caps, one of the objects of the inventor being to remedy the mentioned dlifliculty. V

ll A specific example of this invention is illustrated by the accompanying drawing in which:

Figure 1 is a longitudinal section through the mandrel-bar, piercer-point and work of a tube piercing-mill;

20 Figure 2 is an enlargement from Figure l; and,

Figure 3 is a detail.

More specifically, the drawing shows a tubular mandrel-bar I adapted to position a piercerpoint 2 between the rolls 3 of a tube piercing-mill.

25 The piercer-point is fixed to the mandrel-bar by a mandrel-bar cap that exemplifies the present invention.

This cap includes a socket member 4 screwe into the end of the mandrel-bar I andhaving a 30 mandrel engaging face 5. The socket hole 6 of this 'member is tapered and adapted to receive a similarly tapered end of the mandrel-pin i, this pin having an opposite end fitting the usual hole 8 in the piercer-point 2. This hole 8 is deeper 36 than the projecting end of the pin so that the back of the piercer-point 2 bears against the face of the socket member 4, whereby the pin I is relieved from the thrust the work exerts against the point.

40 Even though the socket member 4 becomes jammed within the mandrel-bar, the pin 1 can be removed when it is necessary to change to a piercer-point of anothersize, the pin 1 then being substituted by another having a projecting 45- end of the proper size.

To facilitate removal of the pin I, it is provided with a transverse hole 9 that is shaped to open on either side of the face Ii when the tapered 'end of the pin 1 is seated in the tapered hole 6 of the member-4. This opening 9 provides a passage for a wedge III which may be driven through this opening 9 to initiate removal of the pin I.

Although a specific example of the invention is disclosed in accordance with the patent statutes, 5 it is not intended that the scope of the invention be limited to this example, excepting to the extent defined by the appended claims.

I claim:

l. A tube mill mandrel-bar cap including a 10 socket member for attachment to a mandrel-bar and providing a mandrelengaging face surrounding a tapered hole, and a mandrel-pin having a tapered end for insertion in said hole and Y an opposite end for mounting a mandrel, said pin having a transverse opening positioned so that when its first named end is inserted in said hole said opening will extend partly to either side of said face, whereby a wedge may be driven through said opening to initiate removal of said pin.

2. A tube mill mandrel assembly including a socket member for attachment to a mandrel-bar with a-socket hole surrounded by a mandrel engaging face, a mandrel-pin having an end for insertion in said hole and an opposite end adapted to project from said hole beyond said face, and a mandrel having a hole fitting the projecting end of said pin and which is deeper than the length of the latter to permit said mandrel to engage said face.

3. A- tube mill mandrel assembly including a socket member for attachment to a mandrel-bar with a socket hole surrounded by a mandrel engaging face, a mandrel-pin having an end for insertion in said hole and an opposite endadaptedto project from said hole beyond said face, and a mandrel having a hole fitting the projecting end of said pin and which is deeper than the length of the latter to permit said mandrel to engage said face, said hole in said member and the first 40 named end of said pin being tapered and said pin having an opening extending to either side of said face when the first named end of said ,pin is inserted in said hole, whereby a wedge may be driven through said opening to initiate removal of said'pin.

. WILLIAM T. WEHMAN. 

